Process of finishing cold-rolled steel



Patented Apr. 5, 1927.

UNITE]? STATES PATENT OFFICE.

JUSTIN n. CROSBY, or raw'ruoxnr, nnonn ISLAND, AssIGNoR'ro J. 1). CROSBY 00.,

or rnwrucxnw, nr'xonn ISLAND, A CORPORATION on NEW YORK.

' PROCESS or FINISHING oopn-nounnsmnn'n.

No Drawing.

This invention relates to a process of finishing cold-rolled strip steel or flattened wire, and has for its main object and feature the production of steel of a very high and a 5 unusual lustre combined .with the requisite degree of hardnessor temper. h

Low carbon cold-rolled strip steel is used extensively in the art for making flat, bent, drawn or spu'n metal products and is generm allyproduced from hot-rolled strips. While during the process of cold-rolling. The temper, that is the. hardness or softness ofithe steel andthe amount of reduction in thickness are, however, bound u'p'with the process of rolling the steel, repeated rolling-s increasing the hardness of the material and reducing its thickness, and therefore the problems of hardness, the reduction. and lustre are intermingledand must be ccordinated;

I find that, bycleaning and drying the steel so as to render .its surface as free from foreign matter as possible. the: steel may have an unusual lustre imparted to it by subjecting it'to a cold-rolling operation by means of dry rolls of hardened steel. 40

By dry rolls is meant that contrary to y the usual practice no lubricant is employed on the surface of the/rolls. The result of this roll ng is that the rolls act against the steel metal to metal with no intervening film of lubricant or other matter and the fine surfacetexture of the'rolls is therefore imprinted upon the steel giving it a high and unusual lustre. The rolling of course also reduces the thickness of the material and increases its hardness. v i v I The cleaning and drying of the steel may be produced in various ways as by. heat, chemicals, mechanical scrubbing or otherwise, one method consistin in combining the ,step of cleaning an annealing or v have found a. method whereby the, polishing operation may be dispensed with. and steel of unusual lustre may be obtained and imparts a a light pass between dry,

Application filed May 4, 1922. Serial N0.'558,532.

softening. These different operations must, however, be properly coordinated with the dry rolling [and thesteps, will. be varied as to their order with respect to thedry rolling and asto their character to obtain dif fercnt degreespf hardness with the same character oflustre.

I have found that a. certain degree of hardness which we call in our shop TH and TQ, (three and a half and three and three quarters) maybe-obtained combined with the requisite lustre proceeding iin the following manner.

The hot-rolled strip steel is reduced vto a proper thickness and is then cleaned by being pickled and limedf'and is then given a number of pas'ses'in the usual manner. the

rolls being supplied with a lubricant. This produces a well known form of strip steelwith a smooth, bright surface. The next steps in the process cons st in annealing and keeping clean and bright the strip so formed. If any foreign matter gets on this strip it should be cleaned ofii. Assuming that thisstrip is clean and bright, between the hard steel, rollers, without any lubricant 'or other foreign matter, so that there is a clean, direct metalto metal 'contact between the strip and roller with what is known as a light pass rolling which reduces its thickness about one one thousandth of an inch polish with a high lustre or satin finish which requires no subsequent polishing. I have found tha-t'the best re sults are obtained with two such light passes with strips about. two one hundreths of an inch in thickness.

Having thus described what I claim is: l The method of imparting a high lustre it is then passed my invention,

or polish to steel strips which consists in,

reducing the steel to the requisite thickness and giving it a preparatory treatment of cleaning, drying and cold rolling'with oiled rollers and thereafter annealing and ,then passing this clean and annealed strip with highly polished steel rollers which slightly reduce its thickness and imparta high lustre or polish.

Signed at Pawtucket. in'the county of Providence and State of 10th day of April, 1922.

JUSTIN n. Caesar;

highly polished". I

Rhode Island, 'this 

